Automatic telephone system



June 19, 1934. M LANGER AUTOMATIC TELEPHONE SYSTEM Filed July l5, 1952 Patented June 19, 1934 n n Y i n. 1,963,586 AU'rollciA'rIoV 'TELEPHONE ,SYSTEM Max LangenvHermsdorf, near Berlin, Germany,

assigner to Siemensr & Halske Aktiengesellschaft, Siemensstadh nearV Berlin, Germany Application July 15, 1932, serial lNo. 622,603

. In Germany July 29, 1.931

Claims. (ol. 11e-16) The invention is inthe nature of an Virnprove-v group: selector, for example the not-shown group ment over a prior application of Langer etal., selector I GW2. Thesecondary lineswitch MWl Ser. No. 594,686, ledv Febrluary .19, 1932, now is'of` the high speed .type and may have from one Patent No. 1,925,261, granted Sept. 5,1933, which f to ytenA trunk lines accessible thereto depending relates to a circuit arrangement for automatic upon its'speed. Switches Vof this type having' a 60 telephone systems so arranged that when im-A vspeed of 2,00 stepsper second havebeen designed pulsesare transmitted for the setting of numerical and as incoming impulses to relay A may be only impulse receivers a lead passing to an impulse reten per second 'contact 17A will be closed long ceiver to be set-by said impulses is placed at the enough for vswitch MWl to'select an idle trunk disposal of the station setting up a connection When this occurs, relay P2 is energized over ak 65 which then has exclusive use thereof. not-shown potential yover the vtest, lead: test The present Vinvention shows a special method potential, wiper of thesecondarylineswitch MWl, of solving the` feature of the invention covered relay P2, contacts a, 22o, rotaryv oir-normal by the said prior application; and this method is Contact 231D of the group'selector I GW1,' earth. l5 that, uponthe reception of animpulse ofpa series, Relay P2 locks 4 itself at 21112 and brings the 70 switching means for the setting of numerical-imsecondary .lineswtch to rest by opening conpulse receivers place a lead passing to an impulse tact 19112.V Y

receiver to beY set by thisimpulse series at the ,When relay A is now energized, the vertical f disposal oiga station setting up aconnection, said magnet HGWl of the group selector I GWl oper- 20 station only being able to utilize this lead. ates over the circuit below due to Contact 11a be- 75 Two embodiments of the invention are shown in ing closed sincerelay Yremains energized during f the drawing. Fig. 1 showsl a group selector I the Yimpulse series as it operates as a slow-acting GWI connected in parallel with a secondary linerelay: earth, contacts 130, 1221/, 11a, rotary olfswitch MWI Which seizes a line accessible` toit normal contact 27u: of the group selector I GWl,

A when the rst impulse series is transmitted by vertical magnet IICrWl,` battery, earth. .The s0 l 40 connecting devices, relay A ls energized over the ,energized due tothe prolonge djenergizaton of delaying the repeating of the rst impulse in such group selectorftakes one vertical step. The nota manner that the secondaryA lineswitch hunts for shown group selector I GW2 reached bythe Vseeand thenguards an idle junctionline between ondary lineswitch MWI executes'a vertical step receiving and retransmitting the impulse. in.v the sameinannerfby influencing its impulse 30 Fig. 2 shows agroup selector I GW21 connected receiving relay corresponding to relay A inv the 85 in parallel with a secondary lineswitch, MW2 lfollowing circuit: earth, contacts 1c, 3a, 2p1, Sp2, which on the transmission of the first impulse of and wiper fof" lthe .secondary lineswitch" MWl. a series hunts for and then guards an idle junction Thus impulses- Yare `repeated by relay A on its line while suppressing, this impulse from the group energizatloncmstead'qf 'on its deenergization as selector whichsucceeds said secondary lineswitch. in the prior circuits. In a Similar manner 'every The individual Switching Operations in detail additional :line loop breaking and closingduring" are as follows: -Y L theimpulse series causes a vertical movement on When the -ca'umg Subscrlber reaches the -a'r' the part of the group selectors yI GWlV and I GW2.

rangement Shown m Fig' 1 Overany associated -At the vend ofthev impulse series, relayY is desubscribers line loop and thereafter relay C over relay A over'thesubscrlbers line loop, wlth. the the test lead 'm a manner of no Interest m uns 'result that, due to the off-normal Contact 26k case. When the subscriber `sends out impulses, Y that Smm Saycuts Off 'the energizing current'for being cl-osedafter the vertical movement of the v relay A passing over the speaking lead, relay Y, y

is energized.. in the following circuit on thenrst .0f the groupseletor I GWlperaeS over earth, release of relay'A: earth, contacts 10c, 9a, windbattery, rotary magnet DGWl., contacts 14u. 16111y ingsI and II oiv relay Y, battery, earth.A In addioff-normal contact 26k ofthe group selectorI tion, due to the closing of contacts 17a an energiz- GWl, contact 2'5dGWl, earth. 'I'he rotary mag- 5o ing circuit for the rotary magnet DMWl'of the net DGWlinfluencescontact 25dGW1 in suclr a 105 Asecondary liileswitchlVIWl is closed over: earth, `manner that said rotary magnet operates as a battery,rrotary magnet DMWl, contacts 17a, 18C, selfl-interrupter andV consequently advances the 19312, relay interrupter RU, earth. The rotary group selector I GWl stepby step in the reachedr magnet is operated in this circuit until lthe seclevel. After itsr vertical movement, the notl ondary` lineswitch MWI has reached an idle shown groupselector I GW2 also *isaldyancedV 110 group selector I GWl, the rotaryY magnet DGWI i step by step in the reached level in a similar manner.

Assuming that the subscriber dials the digit 4 and consequently transmits four impulses, the two group selectors are raised to the fourth level and the group selector I GWl closes the level contact 24dlc4. 'Since an impulse serie-s comprising four impulses corresponds to the traffic direction passing over the group selector I GW2 the energizing circuit for relay P2 is maintained over the level contact 24dk4 after the rotary offnormal contact 23m of the group selector I GWl has been opened. The not-shown group selector I GW2 consequently hunts for an idle junction line in the reached level. The group selector I GWl on the other hand is advanced to the last contact in the fourth level since no junction lines are connected up in this level. Relay P1 is energized when the last Contact has been reached and by opening contact 16111 deenergizes the rotary magnet DGWI and consequently stops the rotary movement of the group selector. Further impulse series are now transmitted to additional numerical impulse receivers over: earth, contacts 1c, 4a, and 57101, over the secondary lineswitch MWl and over the switch wipers of the notshown group selector I GW2 accessible to said secondary lineswitch and the connection nally completed in this manner.

If any other number than four impulses have been transmitted, the level contact 24d7c4 remains open so that after the iirst rotary movement of the group selector IGWl, which opens the rotary oli-normal contact 2310, relay P2 is deenergized and the secondary lineswitch MWl releases the group selector I GW2 by opening contact 21112. The group selector I GWl, however, now hunts for an idle junction line in the reached level and when found is brought to rest on it due to the energization of relay P1 in known manner. Further impulse series are then transmitted over the switch wiper of the group selector I GWl to the succeeding numerical impulse receivers.

The circuits required for the release have been omitted, being of no importance for the feature of the invention. The release may be vcarried out in any suitable manner.

As previously mentioned, Fig. 2 illustrates a second embodiment of the invention in which the rst-received impulse is not delayed when eX- tended further as'in the embodiment according to Fig. 1, but instead is suppressed for the notshown group selector I GW22 which succeeds the secondary lineswitch MW2. |Ihe operations in detail are as follows:

When a calling subscriber has obtained access to the arrangement shown in Fig. 2, relay A1 is energized over the subscribers line loop and relay C1 over the test lead similarly to the previous case. On the transmission of the first impulse series which for example may comprise four impulses, relay A1 is accordingly deenergized and by intermittently closing contact 43a1 causes the vertical magnet HGW21 to operate in series with relay V1. The oir-normal contact 41k of the group selector I GW21 is closed after the ,iirst vertical step and this causes relay Y1 to respond. An impulse circuit for the rotary magnet DMWZ of the secondary lineswitch MW2 is closed on the rst vertical step due to the closing of contact 49ml while relay A1 is deenergized in response to the iirst received impulses, whereupon said secondary lineswitch MW2 hunts freely for a succeeding group selector, for example the not-shown group selector I GW22 in the same manner as the switch MWl (Fig. 1). When this has been reached, relay P22 is energized and by opening contact 511022 causes the release of the rotary magnet DMI/V2. The setting of the secondary lineswitch Mii/'2 is thus completedduring the transmission of the first impulse. The second impulse, that is to say the second release of relay Al, which causes the group selector I GW21 to be raised to the second level, energizes for the first time the impulse-receiving relay associated with the not-shown group selector I GW22 over: earth, contacts 311/1, 32c1, 33m, 39p22, wiper of the secondary lineswitch MWZ. The further impulses then influence both the group selectors. Relay V1 releases at the end of the impulse series and over its contact 471:1 closes an impulse circuit for +he rotary magnet DGW21 with the result that the group selector I GV/2l is advanced step by step. The group selector I GW22 is operated in a similar manner. Due to four impulses having been transmitted which characterizes the junction lines accessible over the group selector I GW22, relay P22 remains energized over the level contact 52dc4. The group selector I GWZl operates until the last contact has been reached since no junction lines are encountered `and relay P21 is energized as soon as this position is reached. The opening of contact 451021 brings the group selector I CTV/2l to rest. Additional impulse series are then transmitted in known manner over the wiper of the secondary lineswitch MWZ and the group selector I GW22.

The trunk lines are, of course, connected to the banks of switches I GWZI and I (3V/'22, so that the proper group is selected by one less step of the switches than there are impulses transmitted in the rst digit to the switch. This digit 4 always causes three steps of the switch and the rst impulse received is not repeated. This insures that the line switch can select a trunk over even a large trunk group before the impulse is repeated thereto and thus denitely prevents it from receiving a portion of the repeated impulse before its seizure is completed.

If the impulse series comprises another number than four impulses, contact 52dk4 is not closed with the result that relay P22 is disconnected at the rotary off-normal contact 5310 of the group selector I GW21 after its rst rotary step. The not-shown group selector I GW22 is then released. The group selector I GW21, however, continues to advance in the reached level until its wipers encounter an idle junction line. When this occurs it is brought to rest due to the energization of relay P21 and further impulse lseries are then transmitted over its switch wipers to succeeding numerical impulse receivers.

The release circuits have been omitted from this arrangement also, since the release is of no importance for the feature of the invention and may be carried out in any suitable manner. What is claimed is:

1. In an automatic telephone system, a trunk line accessible to a trunk selecting automatic switch, means effective following the seizure of said automatic switch for starting said switch to operating to select an idle trunk responsive to the iirst impulse of a series constituting a digit, and means for repeating each of the impulses of the digits subsequent to the first over said trunk line after it has been seized by said automatic switch.

2. In an automatic telephone system, an automatic switch having access to a group of trunk lines, means effective after said automatic switch 'has been taken for use for starting said automatic switch to hunting for an idle one of said trunk lines responsive toV the first impulse of a series constituting a digit of .the desired number, and means for repeating the impulses of said series over the trunk line taken for use by said automatic switch, the said means including means for delaying a allow said switch time to seize an idle trunk before the first impulse is repeated.

3. In an automatic telephone system, an automatic switch having access to a group of trunk lines, means effective after said switch has been taken for use for starting said switch into operation to select an idle responsive to the first impulse of a series constituting ythe next digit in the telephone nurnber, means for repeating the impulses of saidY series over the idle trunk line taken for use by said switch, and means associated with said switch for entirely suppressing the first of said impulses as regards the repeating thereof over said trunk line, whereby the repeating of a muti# lated first impulse is prevented. Y

4. In a combined main exchange and sub-exchange telephone system wherein a switch inthe sub-exchange and a switch in the main exchange ksub-exchange to the repeated impulse so as to taking one of said trunk exchange, and means for delaying the last-named means until the commencement one of said trunk lines are both arranged to respond to the first digit dialled by a sub-exchange subscriber, means in the sub-exchange responsive to the removal'` of the receiver at a calling substation for taking a sub-exchange switch into useto respond to the first digit dialled, trunk lines .leading from the main `exchange and terminating in main-exchangeswitches, means'for lines for use in the subthe action of of the dialling ofthe first digit in thev number, whereby the holding time of said trunk lines is reduced. Y

5. In a telephone system, an automatic switch having group and line selecting motion, a line relay therefor, trunk lines accessible thereto, means for transmitting impulses to said line relay, means associated with said switch responsive to the flrst deenergization of said relay for select- Y ing anidle trunk, means responsive to the subsequent energizations of said relay for operatingr said switch in its group selecting motion and for repeating the received impulses over the selected idle trunk line. Y

j MAX LANGER. 

